Social Security Certificate of Coverage and A1 Form: guide for US expats
If you're a US citizen working abroad, you can end up owing Social Security contributions in both countries on the same income unless a Totalization Agreement or certificate of coverage prevents it.
A Social Security Certificate of Coverage (called an A1 certificate in the EU) is the document that prevents this. It's official proof that you're covered by one country's social security system, so the other country has to waive its claim under a Totalization Agreement.
Key takeaways
- What it is: Official proof that a worker is covered by one country's social security system, exempting them from contributions in another.
- Who issues it: The Social Security Administration in the US; equivalent authorities abroad (the A1 form in the EU, EEA, and Switzerland).
- Who needs it: Self-employed expats, employees on temporary foreign assignment, digital nomads, and remote workers crossing borders.
- What it prevents: Double Social Security or self-employment contributions on the same income.
- What it does not do: Replace your Form 1040 or any other income tax filing – it covers Social Security only.
The Social Security Administration issues the US Social Security Certificate of Coverage when US coverage applies, while foreign authorities issue their own equivalents when their system applies. The US currently has Totalization Agreements with 30 countries, and this certificate is the document that activates the exemption.
What is a Certificate of Coverage?
A Certificate of Coverage is a government-issued document that confirms a worker is paying social security contributions in one country and is therefore exempt from contributions in another. It exists because of Totalization Agreements – bilateral treaties between the US and 30 partner countries that decide which system gets the contributions when work crosses borders.
Without this certificate, both countries can legally demand contributions on the same earnings. With it, the country that's not collecting has formal proof to waive its claim.
US Certificate of Coverage
The Social Security Administration issues the US certificate of coverage when a worker remains under the US system while working abroad. This typically applies when a US employer sends an employee on an assignment of five years or less, or when a self-employed US citizen is temporarily working in a Totalization Agreement country.
The certificate of social security coverage issued by the SSA exempts the worker from foreign social security contributions for the period it covers. The worker keeps paying into the US system and continues earning credits toward US Social Security benefits.
Foreign Certificate of Coverage
When the foreign system applies instead, the foreign country's social security authority issues the certificate, not the SSA.
The foreign certificate works the same way in reverse: it tells the IRS and SSA that the worker is covered abroad, so US Social Security tax and self-employment tax do not apply to that income. The worker must obtain it from the issuing country's authority, since the SSA cannot issue certificates on behalf of foreign systems.
Certificate of Coverage vs A1 certificate: what's the difference?
The A1 certificate of coverage is the EU's version of the US Certificate of Coverage – same purpose, different issuer. The US Social Security Administration issues the US certificate; the EU member state where the worker is insured issues the A1. Both prove which country's social security system applies, and both serve as the legal basis for exempting the worker from contributions in the other country.
The bigger source of confusion is that several unrelated documents share part of the same name:
- Certificate of coverage social security – proves which country's social security system applies and prevents double Social Security tax. This is what this article covers.
- Certificate of coverage health insurance – a HIPAA document showing prior health insurance enrollment, used when switching health plans. Unrelated to taxes.
Only the social security certificates, not the health insurance certificates, have any effect on an expat's tax liability. The table below shows where each document fits.
| Document | Issued by | Covers | When you need it |
|---|---|---|---|
| US Certificate of Coverage | Social Security Administration (SSA) | US Social Security and Medicare contributions | US worker temporarily abroad in a Totalization Agreement country |
| EU A1 / PD A1 | Social security authority of the EU/EEA country where the worker is insured | Social security contributions in the EU, EEA, and Switzerland | Posted workers and people working in multiple EU states |
| UK CA9107 / PD A1 | HM Revenue & Customs (HMRC) | UK social security contributions | UK-insured worker temporarily in the US (CA9107) or in EU/EEA/Swiss countries (PD A1) |
| Health insurance certificate of coverage | Private health insurance provider | Prior health insurance enrollment under HIPAA | Switching health plans, not for tax purposes |
Certificate of coverage vs creditable coverage
A certificate of creditable coverage has no connection to Social Security, self-employment tax, or Totalization Agreements – only the Totalization-based certificate gives an expat any tax relief. A health insurance certificate of creditable coverage example would be a Medicare Part D notice or an old HIPAA prior-coverage document, neither of which affects your tax position abroad.
A1 vs PD A1
The certificate of coverage A1 and the PD A1 are the same document under different names. “PD A1” stands for Portable Document A1, the official EU designation; “A1 certificate” is the everyday term used by employers, freelancers, and tax authorities across EU social security forms.
The certificate is valid across all EU member states, plus Iceland, Liechtenstein, Norway, and Switzerland. A worker insured in Germany who takes a six-month assignment in France presents the same A1 issued by the German authority – France must accept it.
Who needs a Certificate of Coverage?
Any US worker earning income in a Totalization Agreement country where both systems could legally claim social security contributions on the same earnings needs a Certificate of Coverage. Without it, the default rule under SSA Totalization Agreements is that both countries can collect, which means roughly 15.3% in US self-employment tax plus whatever the foreign system charges, often another 20% or more.
The certificate is most relevant for five categories of workers, each with a different trigger.
Self-employed US expats
Self-employed US citizens and green card holders generally owe self-employment tax on net earnings of $400 or more, regardless of where they live – 15.3% of 92.35% of net earnings up to the annual Social Security wage base, with Medicare continuing above it.
The Foreign Earned Income Exclusion and Foreign Tax Credit reduce income tax but do not touch self-employment tax for businesses abroad – only a Certificate of Coverage can.
A US freelancer in France, for example, would owe both US self-employment tax and French social charges on the same income. A Certificate of Coverage removes one side of that equation.
Employees on temporary foreign assignment
US employers sending staff abroad for five years or less can keep the employee under US Social Security and Medicare by obtaining a US certificate. This is the most common use of the US Social Security certificate of coverage – the “detached worker” rule built into nearly every Totalization Agreement.
If the assignment is expected to exceed five years from the start, the worker generally falls under the host country's system instead, and the foreign authority issues the certificate. Some agreements allow extensions beyond five years, but only with advance approval from both countries.
Digital nomads and remote workers
Digital nomads working remotely for a US employer while living abroad are in a gray zone that depends heavily on the host country's rules and the specific Totalization Agreement. If the host country considers the worker a tax resident and subjects them to local social security, a Certificate of Coverage becomes necessary to prevent double contributions.
Remote workers and digital nomads need to check the host-country rules and the applicable agreement; visa status alone does not determine social security coverage.
Business travelers and short-term workers
Short business trips do not automatically remove the need for a certificate, but local rules control; check the relevant authority before travel.
For repeated or extended business travel, a certificate may become necessary even if no formal “assignment” exists. This catches many US workers off guard, particularly in Germany, France, and the Netherlands.
People working in multiple countries
Workers splitting time across two or more countries – common for consultants, contractors, and remote employees with international clients – fall under specific tie-breaker rules in each Totalization Agreement. The agreement determines which single country has the right to collect contributions, and the certificate documents that determination.
In the EU, this is handled by the A1 certificate under the “multi-state worker” rules. Outside the EU, each US Totalization Agreement has its own provisions, generally based on where the worker performs the majority of their work or where their employer is based.
Do I need a Certificate of Coverage? Quick checklist
Run through these six questions to decide whether to apply. If you answer yes to question 1 and yes to any of questions 2 through 6, you almost certainly need a certificate.
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Are you a US citizen or green card holder earning income through work (employment or self-employment)?
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Are you working in a country that has a Totalization Agreement with the US?
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Are you self-employed and earning $400 or more per year?
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Has your employer assigned you abroad for a defined period (typically up to five years)?
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Are you living abroad while working remotely for a US or foreign employer in a way that triggers local tax residency?
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Are you splitting work time across two or more countries with social security systems?
If you answered no to question 2, no certificate exists – there's no agreement to invoke, and you may owe contributions in both systems with no relief available.
If you answered yes to question 2 but no to questions 3 through 6, your work likely falls below the threshold that triggers foreign social security, and a certificate is probably unnecessary.
How Totalization Agreements prevent double Social Security tax
A Totalization Agreement is a bilateral treaty that decides which of the two social security systems collects contributions when work crosses the border. The US currently has 30 such agreements in force. Without one, both countries can legally claim contributions on the same income with no relief mechanism to recover the duplicate payment.
The Certificate of Coverage is the document that activates the agreement: the agreement sets the rule, and the certificate proves it to the tax authority on the other side.
Income tax treaties are not the same thing
Income tax treaties and Totalization Agreements are two separate legal instruments that often cover the same country pair but operate in different parts of the tax code:
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Income tax treaties – cover income tax on wages, business profits, dividends, and capital gains. The US has around 70 of these.
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Totalization Agreements – cover social security and Medicare contributions only. The US has 30 of these.
A country can have one without the other. Australia has both. Singapore has neither. Confusing the two is one of the most common mistakes expats make when planning their tax position – an income tax treaty does not exempt anyone from Social Security or self-employment tax.
FEIE and FTC do not eliminate the self-employment tax
The Foreign Earned Income Exclusion and Foreign Tax Credit reduce US income tax, but neither touches self-employment tax. The 15.3% self-employment tax sits outside both, and a Certificate of Coverage is the only document that removes it.
| Tool | Reduces income tax? | Reduces self-employment tax? |
|---|---|---|
| Foreign Earned Income Exclusion | Yes, up to $130,000 (2025) | No |
| Foreign Tax Credit (Form 1116) | Yes | No |
| Foreign Certificate of Coverage | No | Yes – eliminates it entirely |
A self-employed expat who excludes $130,000 of foreign income under the FEIE can still owe SE tax, but it is calculated on 92.35% of net earnings. On $130,000 of net self-employment income, that is about $18,368 before any wage-base limits.
Foreign social security contributions paid abroad do not count against it either – the only way to eliminate the US side is a foreign Certificate of Coverage attached to the US return.
Read more about how this works in our guide to Totalization Agreements and US expat taxes.
How to request a US Certificate of Coverage from SSA
The SSA does not require a formal application form – employers can request online, by mail, or by fax through the SSA's Office of Earnings and International Operations; self-employed workers generally submit by mail or fax. Requests should be made before the foreign work begins whenever possible.
There is no fee, no standardized certificate of coverage request form, and no IRS involvement in issuing it. The certificate itself is a one-page certificate of coverage letter signed by the SSA confirming the worker's coverage period and the country it applies to.
Step 1: Confirm a Totalization Agreement applies
Check whether the country where the work will take place has a Totalization Agreement with the US. The SSA maintains a current list of all 30 partner countries on its International Programs page – if the country is not on it, no certificate can be issued because there is no agreement to invoke.
If the country is on the list, identify which side (US or foreign) should issue the certificate. As a rule, US workers temporarily assigned abroad for five years or less stay under US coverage and need a US certificate; longer assignments and permanent moves generally fall under the foreign system.
Step 2: Gather the required information
The SSA needs specific details to issue the certificate. Missing information is the most common reason for delays, so prepare everything before submitting the request:
- Full legal name and date of birth of the worker
- US Social Security number
- Country of citizenship
- The country where the work is or will be performed
- Beginning and ending dates of the foreign work assignment
- Name and address of the US employer (or self-employment details)
- Name and address of the foreign affiliate or work location, if applicable
- Whether the worker is employed or self-employed
For self-employed workers, the request must also state that the worker is subject to US self-employment tax under the Internal Revenue Code and is requesting exemption from the foreign system under the Totalization Agreement.
Step 3: Submit the request
The SSA accepts requests through three channels. Employers can submit online; self-employed workers generally request by mail or fax:
- Online – via the SSA's Office of International Programs portal at ssa.gov/international/CoC_link.html. Available for employer requests.
- Mail – Social Security Administration, Office of Earnings and International Operations, P.O. Box 17741, Baltimore, MD 21235-7741, USA.
- Fax – +1 (410) 966-1861. Useful when mail from abroad is unreliable.
Step 4: Receive and use the certificate
The SSA issues the certificate as a signed letter; processing times vary depending on how complete the request is, so apply well in advance.
What the worker does with the certificate depends on the situation:
- Employee on foreign assignment – give a copy to the foreign employer or local payroll, who uses it to stop withholding foreign social security contributions. Keep the original with personal tax records.
- Self-employed expat – attach a copy to the US tax return for any year the certificate is being relied on to exempt foreign earnings from US self-employment tax. Retain the original indefinitely.
- Audit or compliance check – the foreign authority or the IRS may request the certificate years after the fact. Treat it as a permanent tax record, not a one-time document.
When to apply
Apply before the foreign work begins. The SSA can issue a certificate retroactively, but retroactive requests carry real risk – the foreign country may have already collected contributions that are difficult to recover, and some agreements limit how far back coverage can be backdated.
For assignments already underway, apply immediately. For self-employed expats discovering the issue at tax time, the certificate can still be requested and attached to the return for the year in question, but expect SSA processing to take longer than a tax filing deadline allows.
How to get an A1 certificate in Europe
The A1 social security certificate is issued by the social security authority of the EU, EEA, or Swiss country where the worker is already insured, not by the country where the work is being performed.
Each of the 31 participating countries (27 EU member states plus Iceland, Liechtenstein, Norway, and Switzerland) runs its own application process, with its own form, portal, and processing time. There is no single EU-wide office that issues the A1.
The A1 shows which country's social-security legislation applies during the posting, so the host country must recognize a valid form and not collect social-security contributions for the same work while it remains in force.
The rules governing the A1 form across Europe are set at the EU level, but each country runs its own application process.
Who issues the A1 in each country?
The issuing authority is always the social security body where the worker pays contributions on a normal basis. A few common examples:
- Germany – Deutsche Verbindungsstelle Krankenversicherung – Ausland (DVKA), or the worker's statutory health insurance fund (Krankenkasse).
- France – Centre des Liaisons Européennes et Internationales de Sécurité Sociale (CLEISS), or URSSAF for self-employed workers.
- Netherlands – Sociale Verzekeringsbank (SVB).
- Spain – Tesorería General de la Seguridad Social (TGSS).
- Italy – Istituto Nazionale della Previdenza Sociale (INPS).
Each authority publishes its own A1 application form and accepts requests through its national portal. Most now offer fully online submission; a few still require paper filings for self-employed applicants.
The posted worker rule
The A1 is most commonly issued under the EU's “posted worker” framework, which lets an employer send an employee to work in another EU/EEA/Swiss country for up to 24 months while keeping them insured at home. The host country must accept the A1 and cannot demand local social security contributions during that period.
Under the EU posted worker rules, three conditions must be met for the posting to qualify:
- The employer must carry out substantial activities in the home country, not just exist on paper.
- The employment relationship between the worker and the home-country employer must continue throughout the posting.
- The posting must not exceed 24 months. Extensions are possible but require an Article 16 agreement between the two countries' authorities.
If any of these conditions break down – for example, the worker takes on a separate contract with a host-country employer – the A1 may be invalidated, and the host country can claim contributions retroactively.
Self-employed and multi-state workers
Self-employed workers can also obtain an A1, but must show they have been carrying on substantial economic activity in the home country and intend to continue similar activity abroad temporarily.
For workers active in more than one EU country, the residence country usually applies if at least 25% of working time and/or income is there; otherwise, the applicable system depends on the worker's situation, often the employer's head office or, for self-employed work, the centre of interest of the activity.
How US citizens fit in
A US citizen can get an A1 only if they are insured under the EU/EEA/Swiss system that issues it; nationality is not the deciding factor.
A US expat insured under US Social Security and working temporarily in the EU needs a US Certificate of Coverage from the SSA instead, which serves the same function under the bilateral Totalization Agreement between the US and the host country.
A US expat who has switched to a European system (for example, by taking local employment in Germany) can then request an A1 from the German authority for any onward postings to other EU countries.
For a broader view of how these instruments interact with income tax treaties, see our guide to US tax treaties.
Processing times and fees
Fees and processing times are country-specific, so check the issuing authority's current guidance and apply well before the assignment starts. Retroactive A1s are technically possible but inconsistently granted, and some host countries refuse to refund contributions already collected even after a retroactive A1 is issued.
How long does it take to get a Certificate of Coverage or an A1 certificate?
Processing times vary by country and by how complete the request is; check the issuing authority's current guidance.
Backlogs, missing information, and complex multi-country cases can push any timeline past the standard window. Apply before the foreign work begins – the earlier the request, the lower the risk of double contributions during the gap.
| Issuing authority | Typical processing time | Method |
|---|---|---|
| US Social Security Administration | Varies; allow 90 business days | Online (employers), mail, or fax |
| Netherlands (SVB) | Same day to 2 weeks | Online portal |
| Germany (DVKA / Krankenkasse) | 2–4 weeks | Online or via health insurer |
| France (CLEISS / URSSAF) | 4–8 weeks | Online or paper |
| Italy (INPS) | 6–8 weeks | Online portal |
| Spain (TGSS) | 3–6 weeks | Online portal |
| UK (HMRC) | 6–8 weeks | Online or by post |
Apply before work starts
The cleanest approach is to apply at least four to six weeks before the foreign work begins. This gives the authority time to process the request and lets the worker present the certificate to the host country before the first paycheck, preventing foreign payroll from withholding contributions that would later need to be reclaimed.
For employer-sent assignments, the employer usually handles the timing as part of relocation paperwork. For self-employed expats and remote workers, the responsibility falls on the individual, and applying late is the most common cause of double contributions.
Retroactive requests
Apply before the work starts whenever possible. Retroactive treatment is limited and depends on the issuing authority and the agreement involved.
Once a foreign employer or self-employment regime has already collected contributions, recovering those payments depends on the host country's refund process – some refund readily, others require formal disputes and accept refunds only for the current calendar year.
What to do if the certificate is delayed
If the certificate has not arrived by the filing deadline, request an extension when possible and wait to file with the certificate attached. If filing cannot be delayed, discuss whether to file and amend later with a tax professional.
US expats abroad receive an automatic free two-month extension to June 15, and can request an additional extension to October 15 if more time is needed. Use the extra months to wait for the certificate, then file the return with it attached.
What happens if you do not have a Certificate of Coverage?
Without a Certificate of Coverage, both countries' social security systems can legally claim contributions on the same earnings. For a self-employed US expat, this typically means 15.3% in US self-employment tax plus the foreign country's rate – on top of regular income taxes in both jurisdictions.
The exact outcome depends on whether a Totalization Agreement exists at all.
Double Social Security and self-employment contributions
The most direct consequence is paying twice on the same income. In a Totalization Agreement country, the agreement only takes effect when the certificate documents which side applies; without it, both systems collect by default. In a country without a US Totalization Agreement, there is no legal basis for either country to waive its claim, and no certificate exists to fix it.
IRS self-employment tax exposure
A self-employed expat who assumes a foreign social security system has handled the issue remains liable for the US self-employment tax. The IRS does not accept foreign social security payments as a substitute, and neither FEIE nor FTC reduces self-employment tax. Unfiled or underreported amounts accrue interest and penalties – discovering the issue three or four years in can mean a five-figure catch-up bill.
Employer compliance issues
Missing certificates create payroll problems on both sides. The host country may demand contributions on the same wages the home system is already collecting, with the employer on the hook for the foreign side. Penalties can apply even if the worker has long since returned home.
Foreign social security audits
A worker present in a country without a Certificate of Coverage is the default audit target – the authority assumes local coverage applies until proven otherwise. Some countries accept a retroactive certificate and close the file; others assess back contributions and fines, and refuse to refund amounts already collected.
Does a Certificate of Coverage replace Form 1040, Form 2555, or Form 1116?
No. A Certificate of Coverage handles social security and self-employment tax only – it has no effect on income tax filing, which continues to be governed by Form 1040 and the standard expat forms attached to it.
US citizens and green card holders must file Form 1040 every year, regardless of where they live. The certificate runs on a parallel track from income tax obligations and does not replace, reduce, or modify any income tax form.
The certificate is supporting documentation for Schedule SE, where the self-employment tax is calculated. Income tax exclusions and credits like the FEIE and FTC are claimed separately, on their own forms, and follow their own rules.
The Certificate of Coverage covers the Social Security side of expat taxation only – Form 1040 and the income tax forms attached to it are filed in addition, not instead.
| Document or form | What it does | What it does not do |
|---|---|---|
| Certificate of Coverage | Exempts income from US or foreign social security and self-employment tax under a Totalization Agreement | Does not reduce income tax of any kind |
| Form 1040 | Reports worldwide income to the IRS – required of all US citizens and green card holders | Does not address social security or self-employment tax (those go on Schedule SE) |
| Form 2555 | Claims the Foreign Earned Income Exclusion, up to $130,000 for 2025 | Does not reduce self-employment tax |
| Form 1116 | Claims the Foreign Tax Credit for foreign income taxes paid | Does not apply to foreign social security contributions |
| Schedule SE | Calculates US self-employment tax (15.3%) | Is the form a foreign Certificate of Coverage cancels out, when attached to the return |
How the forms work together
A self-employed US expat in France with a French Certificate of Coverage files Form 1040 like any other year. The certificate does not change that obligation.
The expat then attaches Form 2555 to exclude up to $130,000 of foreign earnings from income tax. This handles the income tax side – nothing more.
Finally, the French certificate is attached to exempt the same earnings from the US self-employment tax on Schedule SE. All three documents do different jobs, and none replace each other. The relationship between a certificate of coverage and IRS filing is purely about Schedule SE – everything else on the return continues as normal.
For the full picture of which forms US expats need to file, see our guide to US tax forms for expats.
Common mistakes when requesting or using a Certificate of Coverage
Five mistakes account for most of the problems expats run into with Certificates of Coverage – and all of them are avoidable with a few minutes of planning before the foreign work begins. The cost ranges from a few months of duplicate contributions to multi-year audits with no clean recovery path.
- Assuming a tax treaty equals a Totalization Agreement. The two are entirely separate instruments. The US has around 70 income tax treaties, but only 30 Totalization Agreements – Singapore and the UAE have neither, leaving expats exposed to double Social Security contributions with no relief.
- Waiting until after filing to apply. Many self-employed expats notice the issue only when preparing their return, by which point the certificate may take six to eight weeks to arrive. File an extension and wait for the certificate rather than file without it.
- Confusing health insurance certificates with social security certificates. HIPAA creditable coverage letters and private health insurance documents share part of a name with the Social Security Certificate of Coverage, but have no effect on tax liability. The right document comes only from the SSA or a foreign social security authority.
- Not covering the correct dates. A certificate is valid only for the date range it lists. Extending an assignment without updating the certificate creates gaps where the host country can claim contributions, even if the periods before and after are covered.
- Not checking self-employment status. US workers abroad sometimes assume their income is wage income when the IRS would treat it as self-employment – common for consultants, contractors, and owners of small foreign companies. Misclassifying the income means requesting the wrong type of certificate or missing the need for one entirely.
Certificate of Coverage examples
Three scenarios cover the most common situations US expats face with Certificates of Coverage: an employee on a temporary foreign assignment, a self-employed expat in an agreement country, and a freelancer in a country with no Totalization Agreement at all. Each has a different outcome, and only two of the three have a working solution.
Example 1: US employee sent to Germany
- The situation. A US software company sends an engineer to its Munich office for a three-year assignment. The engineer remains on the US payroll, paid in dollars, with US Social Security and Medicare withheld at the standard rates.
- The outcome. Under the US–Germany Totalization Agreement, the “detached worker” rule keeps the engineer under US coverage for assignments of up to five years. The US employer requests a US Certificate of Coverage from the SSA before the assignment begins.
- The proof. A copy of the US Certificate of Coverage is given to the German employer or local payroll, which uses it to stop withholding German social security contributions. The original stays with the engineer's personal tax records.
- The result. The engineer pays US Social Security and Medicare for the full three years, owes no German social security contributions, and continues building US Social Security credits. No double contributions, no recovery process.
Example 2: Self-employed US expat in the Netherlands
- The situation. A US citizen has lived in Amsterdam for four years, running a consulting business with Dutch and EU clients. She is registered as a zzp'er (self-employed) in the Netherlands and pays into the Dutch social security system.
- The outcome. Under the US–Netherlands Totalization Agreement, a self-employed US citizen who is a resident of the Netherlands and contributes to the Dutch system is generally exempt from US self-employment tax. The exemption only takes effect once she obtains a Dutch Certificate of Coverage from the SVB.
- The proof. The Dutch certificate is attached to her US Form 1040 each year she relies on the exemption. Her Schedule SE shows the foreign earnings but excludes them from the 15.3% self-employment tax calculation, with the certificate as supporting documentation.
- The result. She pays Dutch social security only, no US self-employment tax. She still files Form 1040 every year under citizenship-based taxation, claims the FEIE on Form 2555 to handle the income tax side, and the certificate handles the self-employment tax side.
Example 3: US freelancer in a non-agreement country
- The situation. A US freelance graphic designer moves to Dubai and works remotely for US and European clients. The UAE has no Totalization Agreement with the US and no personal income tax or social security system for most foreign residents.
- The outcome. No certificate exists – there is no agreement to invoke. The freelancer remains fully liable for US self-employment tax (15.3%) on net earnings of $400 or more, with no relief mechanism available.
- The proof. None applies. The freelancer files Form 1040 with Schedule SE and pays US self-employment tax in full. The FEIE on Form 2555 still excludes up to $130,000 (2025) of earnings from US income tax, but self-employment tax is a separate calculation and is not affected.
- The result. Net cost is the full 15.3% US self-employment tax. This is the typical outcome for digital nomads in countries without a US Totalization Agreement. Check SSA's current country list to confirm.
FAQ: Certificate of Coverage and A1 certificate
You apply to the social security authority of the EU/EEA/Swiss country where you are insured, not the country where you will be working. Each country runs its own portal, and an A1 form online application process; some issue the certificate the same day, others take six to eight weeks.
Processing times vary by country, so check the issuing authority's current guidance before you apply.
No. A Certificate of Coverage proves which country's social security system applies and prevents double Social Security tax. Health insurance certificates document private health coverage and have no effect on tax liability – the two share part of a name but operate in completely different areas of law.
Yes, if they are working in a Totalization Agreement country and want to avoid the 15.3% US self-employment tax on the same income that is already subject to foreign social security contributions. Without the certificate, the IRS treats the worker as fully liable for US self-employment tax regardless of what the foreign system collects.
Retroactive treatment is possible in some cases, but is limited and depends on the issuing authority and the agreement involved. Recovering contributions already collected by a host country is a separate process that depends on local refund rules and may take months or years.
It is a one-page document issued by the SSA (or a foreign equivalent like the A1 in EU countries) that confirms a worker's social security coverage period and the country it applies to. The worker presents it to the host country's tax or payroll authority to stop foreign contributions, or attaches it to the US tax return to exempt income from self-employment tax.
The fastest route is the SSA's online portal at ssa.gov/international/CoC_link.html. Mail goes to Office of Earnings and International Operations, P.O. Box 17741, Baltimore, MD 21235-7741; fax is +1 (410) 966-1861. The SSA certificate of coverage has no application fee and no standardized form – the request is made by letter with the worker's details.
They serve the same purpose under different agreements. The Certificate of Coverage in the USA is issued by the SSA under bilateral Totalization Agreements; the A1 is issued by the social security authority of the EU, EEA, or Swiss country where the worker is insured. A US worker abroad uses one or the other depending on which side they are insured under, never both at the same time.
The basic A1 certificate requirements are that the worker is already insured in the issuing country, the foreign work is temporary (up to 24 months under the posted worker rule), and the employment relationship with the home-country employer continues throughout. Self-employed applicants must also show substantial economic activity in the home country before the foreign work begins.
Form A1 is the standardized EU social security document confirming home-country coverage. Each EU/EEA/Swiss country issues its own version through its national social security authority – there is no single EU-wide office or universal A1 application form available across borders.
The US certificate of coverage is issued by the SSA when the US Social Security applies; a certificate of social security coverage from another country is issued by that country's authority when its system applies. Both work the same way under their respective Totalization Agreements – they prove which side collects contributions and exempts the worker from the other side.
The A1 EU form is the standardized social security document that proves a worker is insured in one EU, EEA, or Swiss country and is therefore exempt from contributions in another. It is issued by the worker's home country's social security authority, not by the country where the work is performed.
